When a thin,thin almost gawky George Best first began to reveal his genius, a journalist, noting the time of one of his goals, was told he should remember the date. When, at just after 6pm on 21 February 2009, Roque Santa Cruz became the first man since Samir Nasri three-and-a-half months before to score against Manchester United in the league the time of the goal seemed irrelevant.

That it was not decisive was due to the intervention of a man with whom comparisons with Best do not seem ridiculous. On the hour mark, when Blackburn appeared almost in control and Sam Allardyce had just seen Ryan Nelsen drive a shot against the foot of the post, Manchester United won a free-kick by the left-hand edge of the box around 12 yards out.

The angle was acute, the three-man wall seemed more than sufficient. Cristiano Ronaldo had perhaps one spot to aim at – the top right-hand corner of Paul Robinson's net and found it with staggering precision. He may not be the player he was last season – and it would be impossible even for Sir Alex Ferguson to imagine he might scale those heights. And he might be bound for Madrid, but it is moments like these that make him precious.

This match was in many ways a throwback to last season. Wayne Rooney and Ronaldo were the pivotal figures and Blackburn showed the kind of fight reminiscent of their years under Mark Hughes.

Manchester United may have conceded their first goal since November but they have not conceded the advantage. The day after they lost to Arsenal, Chelsea overcame Blackburn with ease to join Liverpool eight points clear of the champions. Frank Lampard remarked that United might find chasing two teams difficult. In the 15 subsequent matches, they have taken 41 points from 15 games. United know how to chase and they know how to lead.

This was an evening that brought to an end a period of the Premier League season that Ferguson regards as more crucial than any other – the period between the end of the Champions League group phase and the start of the knockout rounds. It was the bit Manchester United have dominated, but now the balancing act between home and abroad has begun again.

Our chalkboard shows the difference Nemanja Vidic makes to the United defence. In the half-hour he spent on the pitch, Blackburn's chances on goal diminished signifcantly.

Edwin van der Sar, who can still claim not to have conceded a league goal since November, was rested. Jonny Evans, the talented young Ulsterman who in the absence of the suspended Nemanja Vidic will be given the task of keeping Adriano and Zlatan Ibrahimovic at bay in Milan, started. Ryan Giggs's presence on the bench and Scholes's position in the centre of midfield suggests the roles will be reversed in the San Siro on Tuesday.

That much José Mourinho would guess. Manchester United's crushing progress through the middle of the campaign might have reminded the Internazionale coach of the way his old Chelsea teams marched ruthlessly through a season, but they rarely attacked with quite this much gusto.

What would have angered Ferguson was that by the time Nani was dispossessed and Andre Ooijer's pass found Santa Cruz Manchester United should have had this match comfortably won. United scored early and there had been times when Blackburn's back four, while trying to deal with Ronaldo, had been pulled apart as if they were on ice. By the time Santa Cruz scored, the champions had enjoyed 81% of possession.

But the chances had not been taken and Santa Cruz, in the 32nd minute, drove towards the Stretford End, held off Rio Ferdinand and took the ball past Tomasz Kuszczak to score. Evans was disappointed but not as much as he was when just before the interval he had what seemed a perfectly good headed goal disallowed by Howard Webb for pushing. For the first time in more than 22 hours and three months Manchester United had conceded in the Premier League. Ferguson had remarked that in the dressing room before kick-off this record had come to dominate the banter. Now there would be no more talk.

In the opening 20 minutes Allardyce could only have hoped his Blackburn side would not be overwhelmed. In this they succeeded, although not by much. Scholes sent one drive whistling past Robinson's post in the opening exchanges. A lovely, curling cross from Ronaldo was cleared from Michael Carrick's head by Ryan Nelsen, who was to unwittingly hand Manchester United what at the time seemed the first of many goals.

Attempting to cut out another beautifully timed ball from Nani, the New Zealander stuck out a leg and diverted the ball into Rooney's path. The striker had perhaps a second to react as Robinson advanced, but slid it effortlessly home. It was his first start for more than a month and there seemed not the slightest hint of rust.